Semiautomatic telephone system



C. A. W. HULTMAN. SEMIAUTOMATIC TQLEPHONE SYSTEM.

APPLICATION FILED DEC. 23, 1918.

- Patented Oct. 3, 1922.

12 SHEETS-SHEEI l.

ab N C. A. W. HULTMAN.

SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATIQN FILED mac. 23. 191B.

1,431,1 16. Patented 0bt.3,1922.

l2 SHEETS-SHEET 2.

61?. W Hui/imam.

c. A. W. HULTMAN.

SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED DEC.23, EH8.-

Patented Oct 1922 0. A. w HULTMAN.

SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED 050.23. 1918.

Patented Oct. 3, 1922.

12 SHEETSSHEET 4.

C, A. W. HULTMAN.

SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED DEC.23,1918.

Patented Oct. 3, 1922.

I2 SHEETS -SHEET 5.

C. A. W. HULTMAN.

SEMIAUTOMATLC TELEPHONE SYSTEM. APPLICATION FILED 05c. 23, 1918.

C. A. W. HULTMAN.

SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATION FILED mac. 23. lama.

1,43 1, 1 1 6. Patented Oct. 3, 1922.

I2 SHEETS-SHEEI 8.

Elli 3% lvmwntar 6'. A" W. Hu/Zimmn.

C. A. W. HULTMAN. SEMIAUTOMATIC TELEPHONEVSYSTEM.

APPLICATION FILED DEC. 23, IQIB- 1,431,1 16. Patenteri 0ct.3,1922.

I2 shms -shzu 9.

Ivan #672,307.

a H. W/IZLZZma/n.

C. A. W. HULTMAN. SEMIAUTOMATIC TELEPHONE SYSTEM.

APPLICATION FIL'ED DEC. 23, I918- Patented Oct. 3, 1922.

SHEET II.

12 SHEETS- mm MQ Imv-enior.

6,6 W. flzz/Zimaln. 5 Z0? M,

SHEEI 12.

Patented Oct. 3, 1922.

c. A. w. HULTMAN'. SEMIAUTOMATIC TELEPHONE ';SYS. TEM.

APPLICATION FILED DEC. 23, 4918.

Patented @ct. 3i, lQEZ,

CARL AKEL WILHELl/I HULTMAN, O1 TOGKHOLhI. EWVEDEN.

$EIlEIAUTO3'tvIA'lI'IC TELEPHONE Application filed December 23, 1918.

To all whom it may concern:

Be it known that l, hum AXEL WILHELM HULTMAN, subject of the King ofSweden, residing at Stockholm, Sweden, have invented certain newv anduseful Improvements in Semiautomatic Telephone Systems, of which thefollowing is a specification.

This inventlon relates to automatic and semiautomatic telephone systemsin which switches or great capacity, for instance one or more thousandlines, are used for establishing the talking connections. Moreparticularly, the invention relates to the group-switching stages ofsystems of this kind in which the connections are established by meansof switches of the line finder type associated with the outgoing linesof a group-switching stage, while the numerical selection is effected bymeans of separate group selectors or equivalent means associated withthe incoming lines and arranged in common to groups lines.

The principal object of the invention is to simplify the switchoperations in the group-switching stages oi such systems oarticularlywith a View to prevent wrong connections. To this end, according to onefeature of the invention, the fixed contacts of each finder switch arearranged in groups or rows each comprising theterminals of a dilterentgroup of incoming lines.

This grouping of the incoming lines and the terminals of the finderswitches lends itself conveniently to obtaining a simple control system,so as to prevent interference in case there are two or more simultaneouscalls into different numerical groups. in such a case finder switchesbelonging to different numerical. groups would he simultaneouslysearching for the calling l nes, there would be a risk of the callingline be ing connected through to a wrong numerical group. To preventthis the group selectors are adapted, according to the invention, tomark the appertaining group out incoming lines only in the finderswitches helonging to the numerical, group selected.

The finder switches of each numerical group will then, evidently beunable, in searching for calling lines, to establish connection withother incoming lines than those which are seeking connection in theparticular group in question. Thus, according to the invention, eachgroup of incoming lines is provided with separate test-contacts SYSTEM.

Serial No. 268,069.

in the different numerical groups of finder switches and these groupmarking contacts are connected up to the group selector of thecorresponding group of incoming lines in such a manner that, after thegroup selector has been set, a test potential is applied only to thetest contacts of the tinder switches belonging to the numerical groupselected.

immediately after the group selection a number of line finder switchesis started to search for the calling line. That one, which first findsthe marked group containing the calling line moves into thecorresponding row of contacts to complete the connection whereas allother finder switches are prevented from entering the corresponding rowby the first finder switch applying a test potential whereby said row isbarred to the other finder switches.

in the arrangement so far described the instance is not taken intoaccount, when are two or more incoming lines of the same group callingsimultaneously to different numerical groups. To prevent wrongconnections also in such cases means are provided, according to theinvention, to prevent more than one call from entering each group ofincoming lines a time, for instance hy marking all lines of a groupengaged as soon as a call occurs on one line and as long as theswitching operation is go ng on.

The invention, and the objects to be obtained in its use, resides in thecertain new and novel arrangement of circuits and parts as will hehereinafter more fully described, set forth in the appended claims, andillustrated in the accompanying drawings, in which Fi ures 14' show thecircuit diagrams for a talking conue tion in a semiautomatic telephoneexrl er 'ording to the invention, adapted to; a nun of subscriberscorresponding to numbers with five digits,

Figure 8 is a scheinatical view of the drivinn device 01 the linefinders,

Figure 9 shmvs a detail oi? said driving device,

Figure 10 shows a detail of the construction of the register switches,

Figure ll shows schematimlly the arrangeinent of the junctions and theconnectingz; switches in an exchange according to Figures l7,

Figure shows diagrammatically a cross ob ii, and shown as consisting ofsingle wires although, actu ll they aomprise two or more in Fl ll tnesubscribers lines AL are connected at the ricorn fr side of the 1.:exchange to the contact fielv s of preseiecting line lind t utgo side tothe s. and at he 0 s contac d of coi'inector L V. Elie connections betwen the pres-looting line iinders nd the connectors ll! are eii'ec ed bymeans o, group selectors 5., to the contact fields of l lead- Which theconductors i t is tru I 1 b are i It M rug; porn the ress f conire- Zedand each or Whicl'i is connected, at the other side, to a conn 301? orrii lie preselectingi line 1 stitute tue pre-selectin s group selectorsS cont it A looting section GS and the connectors LV the line selectingsection A? i preselecting' Li in my copendii'ig patent a lio.268.068.1iled December each ha -e acaoacity of 1000 J pics there Theyines or multileading therefrom and Which are divider 0 two main group,and B lelopipe-lieal bur i oi bare C31 rows each containing between thetwo groups the movable cor i c" arms or": the ich, as S or S which areadapted to be forward and backwards in a horizontal ieudiculr i to thebundles of rther, up or down into one or The bundles oi arr l are a ofsuch switc kind described in the Patent 0. I250 885, granted to me onDecember 18, 1917, and have a capacity oi? 2000 lines. The constructionoi? the connectors is diii'erent from that oi? the preselecting linefinders and the group selectors comprisl switches 5 and bi chiefly, andonly '11 the trunk lines leading from the latter and connecting thesubscribers lines are divided. in four bundles. the contact arms beingnormally arranged centrally with re gard to these bundles and adapted tobe set to one or the other side from the normal position. Each bundlecomprises Vertical rows of 20 lines each.

groups of subscribers lines 3G AG etc.,

i. e. diilerent 2-thousands.

A ociated with each group of ten lines of the trunks Fil is a set ofregisters com mon to all of said lines and comprising five machinedriven register switches SO L, BO S0 S0 wh ch correspond to difrerentdigits of the subscribers numbers and which are set in accordance withthe Wanted number either from the subscribers station in full automaticsystems or from the keyboard in semiautomatic systems. The re ister etalso comprises a machine driven group selector RV and threeelectromagnetically dryen register switches ltlfl RE and BT13 iiorcontrolling the setting of the connector.

The sWitc-hir operaion is principally the following. Upc i a call aplurality of preselecting line 7 i oers b. are started simulneously thesaid iinders then moving forl and backwards in horizontal direcwhilemaking contact with test Wires 3 he diierent vertical rows of contacts.oreselecting line finder, which first finds cical rowcontaining the lineOil the calling subscriber, is stopped in its horizontal moveitfient andis immediately ai terstartr ed iut wards or downwards, the lattermovement ceasing when the contact arms make contact with the callingline. When the particular preselecting line finder locates the verticalrow in 'uestion the latter is seized and marked as engaged '\\"i.i1respect to the other of the prise/looting line finders, so that only oneof them .an. be started vertically.

the same time the group of ten line tindto which said particularpreselecting line finds belongs. is marked engaged, which indication ismaintained till the connection is completed. Thus, only one call can bereceived and eiiectuated at a time in each group of ten preselectingzline finders S The trunk Fil to which he calling subscribers line thusconnected is now marked as calling; at the operators position inquestion. The operator receives the nuniiber wanted, marks it out on thekey out the corresponding tens group and units contact of the groupselector RV, the latter being then set in a corresponding position. Thegroup selector has as many contact positions as there are 2-thousandsgroups of subscribers lines, and these contacts are con nected to testwires s s 8 etc, of groups of S 6 S G. B G etc, of group selectors 8,corresponding to the different 2-thousands The group selector has asmany contact positions as there are EZ-thousands groups of subscriberslines, and is provided with con tacts connected to test wires s s 5 etc.of different numerical groups S G e3 6,, S G etc, of junction finders 8,corresponding to the different 2-thousands. These test wires identifythat vertical row of the finders which contains the calling trunk FL andare therefore located immediately below one and the same row the wiresof which extend through a plurality of groups of switches S Theidentification is effected by a potential being applied to one of saidtest wires, viz that one which extends through the switches of thenumerical group 5 G selected. Similarly another group of trunk lines FL,connected to another vertical row is identified by another set of testwires s 8. etc., connected to the contacts of another group selector,viz that one associated with said other group of trunk lines. Theselection and starting of the numerical group of selector switches S inquestion is effected by means of the same group selector RV but overcontacts and circuits not shown in Fig ure 11.

At the same time as the test wire thus selected is given a certainpotential, the corresponding set of group selectors S is started andconnection is established between the calling trunk FL, and one of saidgroup selectors in the same way as in the pre-selecting section. Wrongconnections which might occur, in case several calls are madesimultaneously in the same marked vertical row of the contact field ofthe group selectors S are prevented by all lines of a vertical row beingmarked as engaged, as soon as a call occurs on one of them. This iseffected as soon as a lead of the trunk F L; is taken into engagement bythe alling subscriber when not only this particular lead, but also allother leads of the same group 8 G or S G. etc., are marked as engaged sothat the whole group is barred for further calls during the establishingof the connection. The setting of the connector LV belonging to thegroup selectors S is then efiected in known manner by means of impulsessent from the connector to the register switches RE RE The invention is,of course, not limited to the use of only one group switching section,if for instance the dii'lerent groups of subscribers are distributed ondifferent exthe invention that in changes, it may be necessary toarrange a first group switching section on one exchange and a secondgroup switching section on another e..-:change. it is only essential tosuch cases one or the other or both group switching sections equippedfor multi-digit group selection, i. e. that each section :torms acombination of two or more single dig; switching sections, theconnection being effected in one step without intervening numericalselection, in which case the latter precedes the connection.

The invention does not exclude the use of double line finders accordingto the principle of double preelection, and this arrangement may in thiscase be applied to the group selecting section as well as to thepreselecting section.

In the arrangement accordil'ig to 11 the particular group selector may,of course, be dispensed with, it instead of it the register switches 50and Sidare so devised that the group in question is marked directly bythe setting oi the said register switches. Even the latter well as theswitches SU 50 and son, may be dispensed with it the marking of the testwires s s and the contacts of the switches RE is effected .directly froma keyboard.

Besides the capacity of the preselecting line tinder switches and theconnectors may, of course, be varied without departing from the spiritand. scope of the invention.

In order to reduce the number of disengaged preseiecting line finders,which are marked for each call, said line finders may be divided insmaller groups in which case, for the purpose of preventing interferencein case two or more calls occur simultaneously in the same vertical rowof the group selectors S and arrangement according to Fig. 13 may beuser.

Each group of ten preselecting line finders it, corresponding to avertical row in the group selector S is divided in three sub-groups, viztwo groups UG, and UG each containing three selectors, and one group ifcomprising four sele :tors, each of said groups having allotted to it aset of registers of which. only the group selectors RV,, RV and ill areshown. Upon a call only those preseleeting line finders S belonging tothe corresponding sub-group, are marked. as engaged. The group selectorsS, are each provioed witlrtwo contact bars KS, and KS, wiich. for thepurpose of illustrating their function, are shown in the drawing asprovided at one side of the contact field oi? the group selectors S Thecontact bar K3, is ofa height corresponding to the three ,iirst linesof: the contact field, and the her K53 is of aheight corresponding tothe sir: first lines. On a call in the group UG the corresponding groupselector marks the test wire .3 as well as the contact bar KS wherebythe group selector caused to pass the three lirst lines of the verticalrow and to search only among the other lines. It a call occurs in thethird group UG, the contact bar KS is marked in a similar manner,whereby the group selector is caused to search only in the third group.

The invention is not limited to the use of selecting switches of thekind above described and does not exclude the use of switches connectedto the incoming instead of to the outgoing lines or trunks of the groupswitching section.

Before the complete course of operation for establishing the talkingconnection is described more particularly, the essential features of theconstruction of the finder and selector switches will be explained withreference to Figs. 8 and 9, which show the driving mechanism.

The movable contact wipers 7:: are provided at the upper and the lowerends of a contact carrier KB, which is guided between rollers B oncarriage V, the latter being in turn guided. in a horizontal directionon a beam VB by means of rollers R The contact carrier KB is carried byan endless cord or rope L fastened to a laterally projecting arm LA. Thecord or rope is carried. round two rope pulleys LS, and

arranged on shafts rotating in stationbearings and over three pulleys LSand LS, mounted on the carriage, the latter pulleys being looselymounted on a common shaft. These two pulleys have actually the samediameter but are shown unequal on the drawing in order that thearrangement of the cord or rope may be indicated. The cord or rope runsfrom the pulley LS, over the pulley LS, and further over the pulleys LSLS, and L back to L5,. The pulley LS, is keyed to a shaft DA, which bymeans of electromagnetic clutches NTK, and MK, (Figures 1 and 5) may becoupled to a. driving shaft (not shown) continuously rotating in thesame direction, and in such a manner that in one case the pulley L5, isrotated to the left and in another case to the right. The contactcar'ier is normally locked to the carriage by means of a magnet VB.provided on the carriage as shown in Fig. 9. It the clutch MK, is o1.erated, while the magnet VB remains unoperated, the shaft DA rotates tothe left, the carriage V being then also moved to the left as the ropein this case is locked to the carriage by the magnet VB and the contactcarrier. In a similar way the carriage is caused to move to the right,it the clutch WK, is energized, while the magnet VB remains unoperated.If, on the other hand, the magnet last mentioned is energizedsimultaneously with the clutch MK or MK, respectively the swing- Imagnet VB is attracted to the beam VB, the carriage being then lockedand the contact carrier released. The latter will therefore be movedupwards, if the clutch MK, is operated, or downwards. if the clutch MK,is operated.

Figure 1 shows diagrammatically the principal parts of the preselectingline finder S, and the appertaining circuits. In this figure only theprincipal circuits are shown, as the circuit diagram for this linefinder is the same as for the group selector S the complete diagram ofwhich is shown in Fig. 5, and whirh is identical with and operates inthe same way as the line finder S As seen in Figure 1, the subscriberstelephone T has its conductors a, 6 connected to the wires A forming thecontact field of the preselecting line finders. The contact field alsocontains two wires 0 and (Z, which together with the wires (0 and 5 forma bundle so arranged that the wipers ia,, 70 and is, mounted on thecontact carrier make contact with the wires a, b, 0 and (Z respectively,when the wipers enter between the wires in the contact field.

The movements of the preselecting line finders are controlled by amachine driven sequence switch SO of any known construction, thecontacts of which are designated 0,, G etc. The figures shown close tothe contact indicate the positions of the sequence switch in which thecorresponding contact is closed.

Figures 2, 3 and 1 show the arrangement at the operators position.Allotted to each operators position is a keyboard TB, Figure 8. andthree sets of registers provided with three groups I, II, III ofbus-bars 1-12, through which the three corresponding groups of leads ofthe trunks FL. can be connected to the corresponding switch of theregisters. Only that one of the sets of registers which belongs to thegroup III, is shown in the drawing. Each set of registers comprises fivemachine driven register switches SO SO (only three of which are shown,Figure l) which correspond to the digit of the subscribers numbers, anda register switch SO 7, SO SO and S0 respectively for each of the otherdigits. Further, there are three electromagnetic register switches RE REand RE for controlling the setting of the connector, and a registerswitch SO for controlling the switching operations.

The machine driven register switches are of the kind which are coupledto a permanently rotating shaft by means of a magnetic clutch and whichare provided with contacts which are broken and closed in differentpositions of the switch. The set of contacts belonging to the differentregister switches are designated E,, E E F, X, Y, Z and the variouscontacts are closed in the ably mounted positions indicated by thefigures. The construction ot the clectro-magnetical register switches a'ipears from Figure 10. Loosely mounted on a con'unon shailt RA arethree toothed segn'ients TS, (only one being shown). the san'ie beingartuated in one direction by a spring til it ratchet pm. SH actuated bya spring engages the toothed se ment and is operated by the armature otthe electromagnet of the register switch in such a manner that thesegment is moved for the distance ol a tooth for each current impulsethrough the clectromagnot. All segments are restored at the time at theend otthe switching operation by one or the other ot two rotatable armslift extinldiug parallelly with the shaft RA and rotatably mounted on ashat't Vii, said arms rotating halt a revolution upon the shaft VA beingcoupled to a permanently rotating shah; by means of a ma ietic clutchAli l, Figure 3, and then carrying with it the segments by actuatingarms Cit projecting from the segmeats.

Figure shows the group selector 95 On the horizontally movable carriagea number of contact wipers KF -KF are provided, which during themovemei'it of the carriage make contact with a corresponding number oftstationary contact bars its ns Prorided on the carriage are, further,three contact bars KS .JIU and ili tfi cooperating with contact wipers ii F lull and Kl? respectirely nursing with the contact carrier Kl Fig.h. The carriage also carri s two test wipers liil and iiIF wh ch duringthe movement of the finder in thehorizontal direction make contact withtest wires i: for testing the diliirent rows oi contacts The movementsof the group selector are controlled by a sequence switch SO thecontacts of which are designated etc.

lligures 6 and '7 show the arrangements at the conncctcn'. The contactfield here divided in tour groups A, U, l) and the contact carriernormally takes up a position centrally with respect to said groups. Thestarting of the connector LY to the lcit or to the right, upwards ordownwards is controllcd, as in the finder switches hy means of twoelcctrouiagnctical clutches "K and Mli Figure 6, and the shifting magnetVli Fig. 7, mounted on the carriage. The switching operation is alsocontrolled by se quence switches SO SO 80 Figure 6, and the ringing iscontrolled by a rotating switch S0 Pig. 1'', the contacts of saidswitcl'ics SO SU and SU being desig nated H to H V to V and K to Krespectively.

The connector is provided with tour sta- Lion; 1 contact bars KS liifillitand which make contact with f our con t ct wipers liil llF lil and Kics cs respectively provided on the carriage. The carriage also carriestwo contact bars KS and. K8 co-operating with two con tact wipers Ki andKl moving with the contact carrier, The contact bar KS is permanently incontact with the contact har KS by means oi? a wiper ii h Keyed to thedriving shatt DA. of the connector are two impulse disks J S and JS fromwhich impulses are set out for controlling the setting of the connector,and the centering disk Ct "for controlling the adjustment oi? themovable contacts in the proper position.

The numerical wiring of the register switches and the connectors as wellas the principal circuits for selecting the trunlr line finders andoperating the connector will appear from the diagram of Figure For thesake of clear representation the registers are shown as consisting eachof a set of ordinary switches having rotating arms and tencontactpositions the same reference letters being used as in Figures 1-? tofacilitate comparison. The contacts E -E of the switches i-U -tl@ areconnected in multiple to the first row of buttons of the keyboard TB,Figure 3.

Similarly the contacts F X Y and of the other. switches SO SQ SU ant SOare connected to the buttons of the corresponding rows of the keyboard.

The switch arms are shown in positions corresponding to the subscribersnumber 8883?. Thus, the switches SU 80 and 550;; are set in their ninthpositions (the first position corresponding to the figure 0) whereas SQ;is set in its fourth and in its eighth position.

Only the switch SU out of the five switches SU -SO is operated owingthese switches being controlled over contects O E l t l l i or o 2101 oruie switcies ob has a set of contacts E E E E and E respectively overwhich. the circuits of the starting relays FR of the differentQ-thousand groups of selectors S are carried. These circuits are furthercontrolled at contacts F o't' so that any one or the 2-thousand groupsmay be selected by setting the switches SU and in accordance with thetwo first digits of the subscribefis number. The numerical wiring thenumbers opposite to the contacts F. l The contacts X Y and Z control these ting or the switches RE RE and BE respectively. The contacts F X andY control the circuits tor setting the connector. The numerical wiringoi the connector will appear from the numbers inserted in the verticalcontact rows of the connector field diagrammatically represented at thebottom of Figure The connector is connected to the registers over thetrunk lines a, b, (i. The clutch MII couples the connector for movementto the left and upwards and the is indicated hy clutch MK for movementto the right and downwards. The circuits of these clutches arecontrolled by relays SR and SR operated over the (Z- and Z)wirerespectively.

The course of operation will first be described in its main featureswith reference to Figure 15. After a calling subscriber has beenconnected by a line finder to an operator the latter depresses thebuttons of the keyboard corresponding to the wanted number whereby thecircuits of the clutch magnets of the register switches SO SO SO and SOare closed through a common relay RR and over the contacts F X,, Y, andZ respectively the sequence switch D being then in its second position.The switches thus rotate till they reach the contact corresponding tothe depressed button when said circuits are opened and the switchesstopped. SU on tie-energizing closes at a contact the circuit or theparticular switch SO corresponding to the position of SO and this switchSO is now set in accordance with the first digit of the subscribersnumher. The sequence switch D is then moved into its third position inwhich the circuit of the relays Fit of the Q-thousand groups of trunkline finders selected is closed over a contact F said trunk line findersbeing thereby started to hunt for the line engaged by the callingsubscriber. One of said line finders establishes the connection and theappertaining connector is thus connected to said line and over that oneto the registers through contacts C (J C of the sequence switch (1 whichis now in its sixth position.

The connector is now to be set in accordance with the positions taken upby the register switches SO SO and SO Thus, determines partly (atcontacts X if the connector shall be started to the left (even hundreds)or to the right (odd hundreds) partly (at contacts X in which hundredsthe switching operation shall take place. SO then determines (atcontacts Y which group of 20 subscribers, i. e. which contact row, theconnector shall have to search for, and SO (at contacts Z togethe withSO (at contacts Y finally determine the subscriber in question to besearched for. SO also determines (at contacts F whether the connector,after having been set in the horizontal direction, shall move up-. wards(even thousands) or downwards (odd thousands) For the movement of theconnector to the left as also afterwards for the upward movement it isrequired that the (Z wire shall be connected to earth, while currentimpulses are sent on the a and 6 wires (or only the latter), and for themovement to the right as also downwards the Z) wire shall be connectedto earth, while current impulses are being sent on the a and 6 wires (oronly the latter).

If the wanted number is 88837 as presumed above one connector isselected, as previously described, out of those containing thesubscribers lines within the 88th and 89th thousands. This connectorwill then send out four impulses on the a wire, before the last hundredsto the left is reached, and then two impulses on the Z) wire in order toreach the second group of 20 within the hundreds in question. Theconnector will then move upwards (even thousands) while first sending animpulse on the a wire, which is maintained while the ten firstsubscribers 20-29 are past, and then 8 impulses on the Z2 wire, wherebythe 37th line is reached.

It will be seen that in the present case the register switch RE hasobtained earth connection at its fifth contact by 50;; and that RE hasobtained earth connection at its second contact by SO while RE has obtained earth connection at its eighth contact by S02.

Upon the completion of the connection with the connector the sequenceswitch D was moved into its fourth position and a circuit 32 was closedthrough the relay SR- which energizes and connects itself in a lockingcircuit. Immediately thereupon the sequence switches SO and SO are movedinto their second positions in which they remain during the horizontalmovement of the connector. The clutch magnet MK operates and theconnector starts to the left sending out four impulses over the a wireby means of the impulse disc J S which controls the impulse circuit 36of the register switch RE The impulse disc 53 is then inoperative as theimpulse circuit over the 1) wire is then open at a contact of the relayR WVhen RE reaches its fifth position which is connected to earth at acontact X, R energizes and disconnects RE which is thus stopped. At thesame time the said impulse circuit over the 5 wire is prepared at R Asthe connector continues to move to the left J8 now sends impulses overthe 6 wire through RE which is moved into its second position. In thisposition the relay R receives current over a contact Y whereby RE isdisconnected and stopped. At the same time the relay R is connected tothe 6 wire and this relay will therefore be operated by the next impulseon the 6 wire. R then connects itself in a. holding circuit and opensthe circuit 32 of the relay SR whereby the horizontal movement of theconnector is stopped. The sequence switches SO and 80;; are now movedinto their third positions in which the relays SR, and SR are againconnected to the b and (Z wires. Further, the sequence switch SO ismoved into its seventh position. A circuit is therefore closed throughthe relay SR over the (Z wire and immediately after the eanne sequenceswitches SO and 59;; move into their second and fourth positionsrespectively. SO then disconnects the relays SR and SR the latter,however, remaining energized over a holding contact. The clutch magnetMrI is therefore again operated (together with the shifting magnet VRand the connector is started upwards. By the sequence switch S0 enteringits fourth position the a wire was connected to the contact bar K5 ot'the connector. This causes a circuit 48 to be closed through the relay Rwhich locks itself over a holding contact and immediately after SO ismoved into its eighth position. During the upward movement of theconnector the impulse circuit tor RE over the 6 wire is at irstmaintained open at a contact of said relay R When the contact wipers otthe connector reach the contact field the circuit l3 of the relay B istransiently opened where by R is caused to release its armature. theconnector moves on, however, said circuit will again be closed over acontact Y as SO is in its fourth position and, conse quently, R willkeep the circuit of RE open as long as the connector wipers passes overthe first ten contacts of the vertical row in question. When leaving thetenth contact the circuit 43 is opened at the upper end of the contactbartllcl of the connector as this contact bar extends only over half thelength of the vertical row. theretore de-energizes and prepares thecircuit of R19 which now receives impulses over the 7) Wire from theimpulse disc Ct. By the seventh impulse RE reaches its eighth positionin which li receives current over the corresponding contact Z BB is thusdisconnected and at the same time the relay P is connected in circuit.The latter is operated by the following eighth impulse on the b Wirewhich corresponds to the last figure of the subscribers number, andconsequently the circuit of the relay SR will be opened and theconnector stopped in the eighteenth vertical position. The setting ofthe connector is thereby completed.

The switching operations for establishin a talking connec 'on will nowhe describe in detail with retcrence to Figures 1 to 7.

When the calling subscriber removes his receiver a circuit 1. Figure l,is closed ore?- the two line branches (a and through the line relay LR.The latter completes a circuit 2 through a starting relay SP. (or SR itthe subscribers line connected to the lower group B of wires) common toten subscribers Belay SR closes in manner which will be more closelydescribed in connection with Figure 5, the starting circuit for a number(for instance of preselecting line finders S which are Flt'""1"t(l atone time in the horizontal direction. Tie pie-selecting line finderwhich first finds the contact row to which the calling subscribers lineis connecterh is caused to stop in a manner which wi l be more closelydescribed in connection ;h Figure 5 by a test relay opening contact [iin the circuit At the same tim i other preselectmg finders of the appertrig group the finders are put in circuit. l.., pie-selecting line r sthei started upwards or downwards respectively. Wh the pre-selectingline i finds lie the calling subcompleted through one y l ly B whichenergizes 1 i5 winding of a test rel a and closes a locking circuit 5through the other w' and a circuit 6 through the cut-oil w y Lg il oithe subscriber.

FIT]

i iii) latter discoi tne line relay L 'l which in turn or he circuit orthe relay Sli all of moving ll hen the test relay the circuits tor theclutch and the shifting magnet Figure are opencrh whereby thepreseiectinsz line tinder is stopped. Hit the re the sequence switchEli) is operno its fourth posiwhich i tion pa a n the third POSlolOll.In the third ition the line branches (in 7) are connected gh thecontacts 0. and C to the trunk The subscriber is thereby connectedoperators position igure subscriber the clearing relays act theirarmathe said line finders which are still bei tl Y ilhe inicrophoncircuit oi the i111 on of the sequence 1 c rcui a call lay R relay inwas closed. The former t-tracts its armature then shortcircuiting thepart of? its winding. whereby the 12 is marked en, agecl, so that rrelay can be operated. At the closed a Clll'tflh c the rteo and moveson. correspond- ,h the calling); ion the relay )ver the circuit 10.whereby ce switch disconnected. W hen ripped, th sequence switch SOD. 3receives ci rent over the circuit- 1 passes into its second position. inis position the contact D is opened,

TUB is operate the s lOO whereby the call-lamp PL shows a flashinglight, its circuit being closed and opened by a rotating interrupter Atthe same time calls may have entered into the two other groups, when thecorresponding call.- lamps are lighted, but only that one corresioiiiding to the subscriber connected through to the operator shows aflashing light. ri hen SO enters its second position, SO F igure 1,receives current over the circuit 12, whereby it is moved into the fifthposition In this position the line branches at, F) 1) connected to thetalking circuit 13,

ligure of the operatorover the contacts J J and. T T.. Further. acircuit let for a relay SR, is closed which in turn closes the circuit15 :For a Sll'pGU/lSOLfJ lamp OLP.

After the operator has answered and received the number wanted, shemarks it down on the keyboard TB, Figure 3, by depressing the corresionding buttons. For each button there are three contact springs it 73,,71. the middle one being operated by the button, so that the contact 7c,is closed and 7a,, :3 is opened. The buttons are arranged as usual infive rows corresponding to the different digits of the subscribersnumbers. Attr the buttons have been depressed they are retained in theirposition by holding magnets FF -FE,, which receive current over acontact D as long as SO is in its second position.

Upon depressing the buttons the different machine driven registerswitches are moved successively into the positions corresponding to thedepressed buttons. their coupling magnets receiving currents throughcommon relay RR, Figure d, contacts of the cor responding registerswitch, contacts 76,, in, at the buttons of the appertaining row, whichare not depressed, Fig. 3, the contact 70,, k at the operated button ofthe same row and the contact Z67, 70 at one or more preceding rows ofcontacts. It is to be noticed that the register switch SO in question isnot started, until the switch SO has stopped, when the latter determineswhich of the former shall be brought into operation, as SS correspondsto the first two positions of SO SO to the two no positions and so on.Af er the last button has been depressed, the operator actuates thestarting button EK, whereby a circuit 1 a is closed extending from earthat the first contact row over the contacts 70 70, in the different rowsof buttons, connected in series, and through a relay SR Figure 2, whichenergizes and puts itself in a holding circuit independent out thestarting button. The relay SR closes a circuit 17 for a relay DUE, whichenergizes and is locked independently of the keyboard. The circuit of DRand BS is then opened. As long as DH is disconnected, the correspondinggroup is barred for further calls. When DR deenergizes, the sequenceswitch $0 Figure 1, receives current over the circuit 18, wherebyv it ismoved into its sixth position.

When SR attracted its armature the se quence switch SO received currentover the circuit 19, whereby it was moved into its third positionprovided that the relay RR, Fig. i, is deenergized, ie. that allregister switches have stopped moving. In the third position of SO saidregister switches are disconnected. Further, the circuits of the relaySR, and SE are opened and also the circuit of the holding magnets FE --llil Figure 3, isopened, whereby the buttons of the keyboard are restoredto their normal position. When DR, Figure 2, was deenergized, thecircuit of the relay TUB was opened, whereby the sequence switch SO wasdisengaged, so that it now may hunt for another group, where a call hasentered.

lVhen SO enters its third. position the negative pole of the battery isconnected tl :ough the resistance lV, Figure 3., over certain contactsin SO and the switch SO in question to the test wire 8, Figure 5, of thegroup of ten preselecting line finders S, in the group of groupselectors S corresponding to the selected 2-thousands. In a similarmanner the negative pole ofthe battery is connected over a contact DFigure 3, and contacts on the switches SO and SO to a bus-bar'SS, Figure5, for said group of selectors S whereby a number of starting relays F,R,-F R, are energized. The latter close the starting circuits 20 forsaid selectors, which are then started at one time in the horizontaldirection. The group selector, which first finds the vertical row, towhich the calling line or trunk FL is connected, closes a circuit 21through one winding of the appertaining test relay lay R and the testwiper KF The test relay energizes and connects its second winding into alocking circuit 22. At the same time the contact row in question isbarred to other finders by the test wire 8 in question obtaining directearth connection over contacts of the test relay Lq R As the startingcircuits 20 contain the clutch magnet MK all group selectors are startedto the left. If the group selectors should not find the contact row inquestion during their movement to the left, the move ment isautomatically reversed, when the carriage reaches its outer leftposition, the contact spring KF then closing a circuit 23 through ashifting relay HR, which con nee-ts the magnet MK in circuit. The relayHR is then locked over its contact 2e and the relay will thereforeremain current can rying, till the relay F1 1 deenergizes or till 25 isopened in the opposite end a contact position of the carriage.

When the test relay Lg R attracts its

